Welcome to the Society for the Management of Spasmodic Dysphonia.

Our organization is devoted to making resources and information available to the general public about Spasmodic Dysphonia (SD). There is currently a lot of uncertainty and misinformation about causes, symptoms and treatment options. The Society and this website is aimed to dispel the myths and provide you with up-to-date and accurate information.

The Society makes available – through this website – information about SD, stories from people who suffer from SD, discussions of treatment options and other resources. We offer information about all types of spasmodic dysphonia.

If you are unfamiliar with SD, scroll down on this page for some basic facts and information. If you are interested in more detailed information, please review our sections with articles, resources and books.

We hope you find this service useful, and find the answers that help you. Please contact us if you have any comments about this website. Also, we welcome contributions from anyone who has experience with SD – either directly or through a family member.

This website does not promote any particular treatment option or service provider. Please do not post with offerings of any service – we will remove such postings.

Best wishes,

The Society for Management of Spasmodic Dysphonia

Basic information about spasmodic dysphonia
SD is a focal form of dystonia, that involves sudden involuntary muscle movements or “spasms” of the vocal cords causing interruptions of speech and affecting the voice quality. It can cause the voice to break up or give it a strained, or strangled quality.

Typically, a distinction is made between three forms of SD: adductor dysphonia (where sudden involuntary muscle movements or spasms cause the vocal folds to slam together and stiffen), abductor dysphonia (where sudden involuntary muscle movements or spasms cause the vocal folds to open) ad mixed dysphonia (which involves muscles that open the vocal folds as well as muscles that close the vocal folds).


The causes for SD are not fully understood. For a long time there was a debate whether it is a neurological disorder or psychologic. Although the latter cause has been largely proven not to be accurate, many people still tend to be diagnosed with a psychological disorder. There are several reasons for this: first the symptoms (spasms) cannot be seen and is therefore not the result of a visual exam, and secondly SD is a rare disorder and many physicians have not heard of it, and thirdly the symptoms can vary irregularly and therefore both patient and physician may question the seriousness or even reality of the condition.

Treatment options include speech therapy, botulinum toxin (botox) injections, and cutting a nerve to the voice box. The success of these treatment options differ from person to person: there are instances where each of them have been successful. Also, physicians and scientist have not been consistently able to reproduce the successes described by others. Below is a brief description of the treatment options. For a fuller descriptions, including research on these options, please see our articles and book section.
Treatment by voice therapy
Voice therapy (or behavioral therapy) may reduce the effects of SD in mild cases. Individual practitioners report different results, while some organizations question the effectiveness. It is the least intrusive therapy option, and at the same time the most difficult since it involves re-learning of behavior patterns.
Treatment by botulinum toxin injection
Botox is injected into the muscles that are spasming. It interrupts connection between the nerve and the muscle and thereby weakens the muscle. Because nerves are very good at redeveloping and making new connections to the muscle, the effect of the botox injection typically wears off. The therapeutic effect of the injection lasts for about four months, and the injection would then need to be repeated.
Treatment by cutting a nerve to the voice box

Many physicians have tried to treat SD by cutting or altering the nerve supply to the voice box. Early results have been encouraging. However, the disorder returns for many people after months or years. It is not full understood why the effect or surgery is only temporary. It is probably rooted in the complexity having to do with the brain abnormality underlying dystonia.